The invention relates to a photoresist composition and a method for forming a pattern in a semiconductor device and, more particularly, to a photoresist composition and a method for forming a fine pattern that overcomes resolution limits of a lithography process during the semiconductor fabricating process.
It is difficult to form line/space patterns of 50 nm or less in size by a one-time exposure using 1.0 (or less) numerical aperture (NA) ArF exposure equipment, even when employing an immersion lithography process. To improve resolution in lithography processes and increase process margins, diversified research on double patterning has been carried out. Double patterning is a process wherein a wafer coated with a photoresist material is exposed using two masks, and then developed. Double patterning is used primarily for complicated patterns (not simple lines or contacts), or for exposure of dense patterns and isolated patterns to increase process margins. The double patterning process involves exposing and etching a first pattern to double its pattern period, and exposing and etching a second pattern having the same pattern period between the first pattern. Since the second mask and etching processes are performed after the first mask and etching processes, a degree of overlay can be measured. In relation to this misalignment and other factors, defects may be overcome and desired resolutions can be obtained. However, this technique increases the number of process steps, thereby complicating semiconductor assembly and increasing production costs.